Tension member for concrete construction.



7 '1. W. JENKS. I TENSION MEMBER FOR CONCRETE CONSTRUCTION. APPL-IUA'IIDH TILED APR. 11, 1907.

952,259. Patented Mai. 15,1910.

inventor 213/111, M a ms jxmsmks THOMAS 'w. JEN-KS,

OF BELLEVUE. PENNSYLVANIA TENSION MEMBER FOR CONCRETE CONSTRUCTION.

Specifit ation of Letters Patent.

Patented Mar. 15. 1910.

Application filed Ayril 11. 1907. Serial No. 367.488.

To all whom it may concern:

Be it known thatl, 'lnouxs ll. Ji-zxns. a citizen of the. l nited States. residing at Rellevuc. in the county of Allegheny ztl.'l

'State of lennsvlvania. have invented a ne Improved 'l cnsion Mcmlicr for Concretc Construction, of whi h the following is a specification.

My invention relates to reinforcing memlicrs adapted to take up the tensional stresses set up in the hottoms ot' com-r te beams and slahs or wherever it mayv he used to advantage. and the object of my improvements is to provide a memhcr of this kind which shall he so formed that the best possible union shall he attained between the concrete and metal. The reinforcing member consists ot a rolled metal har having a plurality of concaved or inwardly recessed or curved t'accs terminating in intervening longitudinal edges and forming longitudinal at the corners of the bar, and transverse rihs extending :1c1'0-:s the recessed faces at intervalsand merging into the longitudinal rihs.

In the acctmipanying drawing which is a perspective view of a bar showing one form of my invention, the body -1-- of the bar is generally rectangular in cross section with its sides forming segments of cylinders and thus forming grooves -2. Cross rihs -Ir extend across these grooves. thus forming pockets for the reception of the coucretc. For ease of rolling these cross l'ihs are preferably staggered around the bar. and to provide greater contact surfaces the rihs may he made convex. Another advantage of staggering these rihs is that the stress s occasioned by the pressure of the concrete against the ribs are more equallv trail niittcd to the lmdj. of the bar. The deep pockets thus formed conducc to large proje tions of concrete which projections have even curved surfaces devoid of proje ting angles which are always a source of weaknes 'lhc concave form of the pockets assures the greatest area of contact heiween the rilzs I s and the concrete in the pocle cts. thus providing for max mum crushing stresses of the concrete at those points. The spacing of the ribs at consideraljile distances permits the shearing area of the concrete in the. pockets to he at a maximum, while the convex form of the ribs provides great hearing surfaces hetwceu the concrete and the ribs to taizc up the compression stresses;

Having now explained ni v improvements, 'vhat I claim as myinveution and desire to s-curc by Letters: Patent is 1. A metal hair for construction of reinforced concrete having a plurality of in-' u'ardly ciu'ved faces forming longitudinal rihr at the corners of the lmr. and a series of trar reise rihs extending entirely across the said faces and merging into said longitudiral ribs.

'3. metal har polygonal in cross section for ccustructimis of reinforced concrete ha ing a lurality of faces each form d with a plurality of depressions. and each of said depres ions lieing formed by an inwardly curved .izrface and h transverse rihs joining the mtstandiug parts of said inwardly curvui surface.

3. n tal bar for reinforcing concrete comprising a solid l)t)(l generally rectangular in cross-section with the edges slightly blunted and theentire sides concave and slthstzllllinll segments of circles. and rihs extending acro s said sides to form pockets for the reception of the concrete the outer surfaces of the libs heiug convex. and forming segments of circles reversely arranged.

In testimon whereof I have signed this npli ation in he presence of two suhscrihng' witne ses. I

THOMAS \V. .l PINKS.

\Yitnesscs Emvann PAHFJSEN, 't'. L. i.\NN. N0. 

